This invention relates to systems for removing moisture from a gas and more particularly to systems for dehumidifying air and having the capability of being regenerated thermally.
Silica gel and other similar desiccants have been used for a variety of purposes associated with their adsorbent properties. These include their use in the catalytic processing of organic compositions as illustrated in U.S. Pat. Nos. 2,265,389 and 2,882,243 and moisture absorption as illustrated in U.S. Pat. Nos. 3,141,729 and 4,341,539. In general, with silica gel, it is often in the form of a multiplicity of separate ground particles carried on a suitable support. In this form, the usable surface area of the silica gel for moisture adsorption is limited by requirements associated with its use. The silica gel particles are often sized sufficiently large to reduce losses by attrition and are located in closely packed arrangements to resist movement. In some instances, they are modified to include channels to the interior to increase the usable surface area for adsorption. However, the size and limited exposed surface area limits their effectiveness. Also, regeneration of the silica gel often requires a separate and complex processing operation to remove the adsorbed moisture.
One object of the invention is a desiccant having a large surface area available for moisture adsorption compared to its volume. A second object of the invention is a desiccant which may be regenerated within a relatively short time. An additional object is a dehumidification system utilizing a desiccant capable of being regenerated. Another object is a desiccant capable of being regenerated by the use of a low cost source of heat. These and other objects will become apparent from the following description.